Video: Teen drama turned murder

It happened in a small town in the Heartland to two teens probably not very different from ones you know. There seemed nothing to suggest they were capable of joining together in a cold-blooded murder. It began with a typical teenage drama: a love triangle. But this triangle was different from most. It ended with a crime the people of this small town may never forget. Airs Saturday, Oct. 20, 8 p.m.

At its heart, this is a story of ordinary teenage love and jealousy that ended in extraordinary pain.

It begins along the Mississippi river in East Moline, Illinois, with a vibrant 16-year-old girl named Adrianne Reynolds.

Tony Reynolds, Adrianne Reynolds’ father: She always liked singing...

Tony Reynolds’ daughter often felt more comfortable in front of a crowd than in the middle of one. She’d spend hours belting out songs in preparation for a school talent show.

Reynolds family

16-year-old Adrianne Reynolds on her birthday.

Tony Reynolds: We heard all the practicing for weeks. She’d make the whole house rattle.

Joanne Reynolds, Adrianne’s stepmother: You didn’t know if it was her singing or was it the radio. I couldn’t tell—distinguish.

Her stepmother, Joanne, loved to hear her sing, even though Adrianne’s coming to live with them turned their quiet home in western Illinois a bit upside down. Adrianne had moved from her mother’s house in Texas because the two weren’t getting along.

Joanne Reynolds: The kids here called her “Texas” because she had that cute little Southern accent and the kids liked it.

“The kids” were students at this alternative high school aimed at helping teens who struggled to fit in at traditional schools. When Adrianne arrived in November 2004 at age 16, she had no high school credits to her name.

Tony Reynolds: Her biggest problem was she didn’t like school; she didn’t like homework.

While her parents were concerned about her education, Adrianne was focused on her social life. She was a girl in a hurry and crazy about boys. One boy she eventually spent some time with was Cory Gregory, a student at her school.

Cory Gregory: Adrianne was a pretty cool person. We started talking. We talked on the phone for like four or five hours.

Adrianne also wanted girlfriends and she struck up a friendship with Cory’s close friend, Sarah Kolb. But Adrianne’s dad did not approve.

Tony Reynolds: I only met her once, and my first impression was a thug and a freak. She was dressed all in black, had piercings and everything.

Joanne Reynolds: She kind of had a Goth look.

Stafford: Is Adrianne into the Goth thing at this time?

Tony Reynolds: Never.

Stafford: But why do you think she’s attracted to Sarah?

Joanne Reynolds: I think she wanted a friend.

Tony Reynolds: She just wanted friends. It wasn’t, per se, just Sarah. She wanted to be everybody’s friend.

Though her father didn’t like Sarah, he felt Adrianne’s transition to the new school was going well two months after she arrived. He didn’t sense anything was wrong when he said good night to his daughter on the evening of Thursday January 20, 2005.

Tony Reynolds: I always tell her I love her. She said, “I love you, too.” And I went like that [a gesture] and she gave me a kiss. And that was it.

Her father went to his truck driving job at 4 a.m. the following morning, so Adrianne’s stepmom got her ready for school.

Joanne Reynolds: I woke her up that morning and I just asked her, “Do you have work tonight?” She said, “Yeah, at five.”

But after school, Adrianne did not come home to change into her uniform for work at a Checkers fast food restaurant.

Tony Reynolds: She wasn’t an angel or anything, but she always—she had never not come home from school. Never.

Stafford: So do you call Checkers?

Joanne Reynolds: No, we ran up there. Got in our cars and ran up there. And no, they hadn’t see her. And we started calling everybody we could think of.

Stafford: At what point do you call the police?

Joanne Reynolds: Eight o’clock at night.

Police thought she might be a runaway, but her parents said she hadn’t packed any belongings and she hadn’t picked up her paycheck at work.

Tony Reynolds: I said, “You know, you’re not going to make me believe that a kid run away from home and didn’t even bother to get her paycheck.”

Adrianne’s friends told the police she’d left school that day for lunch with Sarah Kolb, Cory Gregory and another boy. An officer phoned Sarah at home to see if she’d seen Adrianne since then.

Police (police interview): Okay, you had contact with her today?

Sarah Kolb: Yes, I did.

Police: When was that?

Sarah Kolb: Uh, in between 12:30 and 1:00.

Police: Were you and Cory giving her a ride somewhere?

Sarah Kolb: Yes, sir.

Sarah told the officer that Adrianne did not want to be dropped off at home so they let her out at a nearby McDonald's.

Sarah Kolb: Because she said that she didn’t want her parents to see that she was in the car with a boy. And before when I had hung out with her one time, she told her parents that Cory was my brother and he’s not.

Police: OK.

Sarah Kolb: So I dropped her off at McDonald’s, which is like right across the street from her house.

Police: Right.

Sarah Kolb: And that was the last time I saw her.

Police: You haven’t heard from her since then?

Sarah Kolb: No, I haven’t.

Sarah suggested Adrianne had probably run away and expressed concern for her friend.

Sarah Kolb: If you do hear anything, I would appreciate it if you would call me and let me know.

While it was true Adrianne’s dad didn’t approve of her being in a car with boys, something didn’t make sense to him. Why would Adrianne worry about being dropped off at home around noon when he didn’t come home from work until hours later?

Tony Reynolds: That was the first thing that hit my head. I’m never here at noon.

Stafford: And Adrianne knows you’re not here at noon?

Tony Reynolds: Right, exactly. She knows I’m never here.

Stafford: What does that feel like at this point?

Tony Reynolds: I’m scared.

The more Adrianne's parents learned about her relationship with Sarah, the more frightened they became.

Stafford: Was Sarah bisexual?

Cory Gregory: Yes.

Stafford: Was Adrianne?

Adrianne Reynolds’s parents drove around desperately trying to find their daughter. They also discussed everything they knew about Sarah Kolb and Cory Gregory, the teenagers who said they dropped Adrianne off at McDonald's just before she went missing.

Rob Stafford, Dateline correspondent: So what do you think about the story the kids are telling you?

Tony Reynolds, Adrianne's father: I didn’t believe it, because if they dropped her off, she’d be here.

They began to wonder if Adrianne’s relationship with the two teens had something to do with her disappearance. Just a few days earlier, Adrianne confided in her stepmom, saying she was interested in Cory and that could be a problem for their friend Sarah.

Joanne Reynolds, Adrianne’s stepmom: And she even told me that Cory told Adrianne that they had to keep their friendship a secret from Sarah. That Sarah would get mad.

Stafford: ‘Cause Cory was worried that Sarah would be jealous?

Joanne Reynolds: Uh-huh.

Tony Reynolds: She liked to be the one in control of everything.

Control— that was something Cory Gregory had learned early on about Sarah Kolb, but it was not a turn-off to him. In fact, it was an important part of their relationship, a relationship that came to define his life.

Cory Gregory: I met Sarah at the mall. And then we ended up going and smoking weed behind Gordman’s Department Store and then we just started hanging out everyday from there.

Cory had been a good student and a fun-loving boy, but by the time he was a sophomore, he had fallen in love with pot, heavy metal music and especially Sarah Kolb.

Stafford: What attracted you to Sarah?

Cory Gregory: She was just dressed how we dressed - the big, baggy pants, black band T-shirts and—

Stafford: Kind of that Goth look?

Cory Gregory: If that’s what you wanna call it—yeah.

They starting going out, but that lasted only a few weeks. Sarah said she just wanted to be friends but they became best friends— inseparable.

Sarah Kolb

In fact, Sarah convinced Cory to transfer to her school, where she had a reputation as a very angry girl. “What is it with people today?” she wrote in her journal. “It seems as if everyone is driving me crazy, and all I want to do is slaughter them like the f*ng sheep they are!”

Stafford: What’s she so angry about?

Cory Gregory: I don’t know. She just has an anger problem, really. She just gets mad over the littlest things.

Stafford: What’s Sarah like when she gets mad?

Cory Gregory: Just off the wall, really, you know? Yelling, screaming, throwing things…

Cory’s parents, Bert and Teresa Gregory, did not witness Sarah’s anger but they worried about how infatuated with Sarah their son had become, even though Sarah told him she just wanted to be friends.

Teresa Gregory, Cory’s mother: Cory really wanted to be boyfriend and girlfriend. Really bad. And I think Cory, in the back of his mind, thought if he just hung in there long enough as her best friend, she would someday see him as a boyfriend. Because he was loyal to her and hung in.

Cory expressed his feelings for Sarah in a letter: “I love you. I have since I first laid eyes on you.... You are all I think about.... You are the only one I felt I could speak my emotions, and I want you to know I’ll always be that for you.”

Adrianne’s arrival at their school in November 2004 complicated the relationship between Cory and Sarah.

A friendship between the two 16-year-old girls began in the most benign way: with notes being passed in school.

Sarah Kolb started by asking Adrianne a few innocent questions: “What’s your favorite color?” “What are some of your favorite bands?” Sarah said she liked heavy metal music and the color purple.

Cory Gregory: She was - her and Sarah were talking about dating.

Stafford: Sarah and Adrianne were talking about going out with each other?

Cory Gregory: Yes.

Stafford: Was Sarah bisexual?

Cory Gregory: Yes.

Stafford: Was Adrianne?

Cory Gregory: Uh, she was bi-curious.

Stafford: She was thinking about it.

Cory Gregory: Yeah.

This sexual tension between Sarah and Adrianne quickly became apparent in their note-passing. Adrianne asked Sarah: “What is the most you’ve done with a girl? Are you bisexual or straight lesbian?” Adrianne implied to Sarah she was bisexual, which was news to her father.

Tony Reynolds: I think Sarah might’ve said, “Well, I’m bi” or whatever, and I would think Adrianne would say, “I am too.” But the two never got together.

In fact, something pushed the girls apart. Their relationship disintegrated after a party at this house in December.

Could that be a clue to Adrianne’s disappearance a month later?

Cory Gregory: She was talking and flirting with the other boys—Adrianne was, so Sarah got mad about that.

Stafford: Sarah’s jealous?

Cory Gregory: Yeah, Sarah got jealous.

Stafford: Because Adrianne’s spending time with boys and Sarah wanted Adrianne to spend time with her?

Cory Gregory: Pretty much, yeah.

Adrianne ended up having sex with one of the boys at the house, which enraged Sarah.

Cory Gregory: She started calling her a “slut” and a “whore” and words like that.

Cory says the next day, Adrianne slept with another boy at the house, angering Sarah even more.

Cory Gregory: Adrianne tried to call Sarah like every single day and Sarah just answered the phone and yelled at her or hung up on her.

Stafford: Did Adrianne seem that desperate to have friends and not be rejected?

Cory Gregory: Adrianne wanted to fit in, you know? And Sarah got his attitude like “Oh, I’m number one,” you know?

Despite the rejection, Adrianne kept trying. On December 15th, she asked Sarah: “How come you don’t talk to me?”

By December 30, Adrianne wrote again, saying Sarah was “just looking for a way to not be” her friend.

Cory Gregory: After that first day at that party, they’ve fought every single day I’ve seen them since then. Sarah would make her cry.

At the time, Adrianne’s parents didn’t know about these letters, but Adrianne had told her stepmom that Sarah was bad-mouthing her and even threatening her.

Joanne Reynolds: Adrianne told me that she was scared.

Stafford: Scared?

Joanne Reynolds: Uh-huh.

Stafford: Of Sarah?

Joanne Reynolds: Uh-huh, and that there had been a lot of fighting at school.

Joanne Reynolds: Just Sarah yelling at her, telling her to commit suicide.

Still Adrianne would not let go of Sarah and wrote her saying: “I wanted a chance for us to start over again and to at least be friends.”

“Why do you hate me so much and why do you want me to die?”

To complicate things even further, in mid-January, Cory and Adrianne began hanging out a bit - but without Sarah.

Cory Gregory: We kissed a couple times, but that was about it.

Stafford: Did Sarah know that you were seeing Adrianne?

Cory Gregory: I told Sarah and she got mad and hung up the phone on me.

Cory told his mom about the tiff with Sarah.

Teresa Gregory, Cory’s mother: I said, “Cory, Sarah’s not your girlfriend, you can hang out with anybody you want. She has no right to tell you who you can and cannot be friends with.” He said, “I know, Mom, that’s what I told her.”

Cory and Sarah made up the next day, but she was furious at Adrianne for moving in on her best friend and she wrote about it in her journal on Friday, January 21, 2005, the day Adrianne went missing. “Stupid bitch needs to back up off my Kool-aid! She’s going to give him a note. Yeah well I’ll (f*ng) kill her.” But surprisingly, later that same day, Sarah was nice to Adrianne and, as she told police, even gave her a ride at lunch time, the last time she was seen.

Cory Gregory: They’re acting like they’re friends again. So I figured nothing of it because Sarah does this all the time. She’ll hate someone one day and she’ll be friends with them the next.

Why would Sarah give a ride to a girl she clearly did not like? Police would soon be asking her that very question.

Police were trying to piece together everything that happened in the hours before Adrianne Reynolds disappeared. So they continued to call Cory Gregory and Sarah Kolb: the last people known to have seen her on Friday, January 21, 2005.

Police (police phone interview): Hello, is this Sarah?

Sarah Kolb: Yes, it is.

Police: This is Officer Allen, East Moline Police Department.

Police: Are you friends with Adrianne Reynolds?

Sarah Kolb: To be honest, no. I don’t like her

Sarah explained their rocky relationship and the officer wondered why she’d give a ride to Adrianne, a girl she didn’t like.

Sarah Kolb: We got into an argument at school.

Police: Um hum.

Sarah Kolb: And I was like, “Well, let’s talk it over at lunch.” She had been hanging out with my friend who likes me and I like him, but she likes him and we got into an argument about that because she wouldn’t leave him alone.

Adrianne had gotten into Sarah’s car along with Cory and a friend named Sean McKittrick. Sarah and Cory first told police that they dropped her off at McDonald’s but investigators were about to find out there was much more to that story. In fact, Sarah was about to drop a bombshell.

Sarah Kolb: I’ll be honest with you. I hit her.

Police: Okay.

Sarah Kolb: She hit me back.

Police: Okay.

Sarah Kolb: And all props to her, she hit me pretty hard too.

Sarah says the fight occurred inside her car, which was parked at a Taco Bell restaurant during the busy lunch hour.

Sarah Kolb:And I swear to God, you know, she was crying. She’s like, “I’m afraid that you,” you know, “you’re going to beat me up.” I was like, “You know what? You’re not even worth it.” I’m not going to get in trouble over some stupid minor who is a skank. And I was like, “Just keep it simple. Stay away from me and stay away from Cory.”

Cory told us he witnessed everything.

Cory Gregory: And Sarah just kept screamin’ and screamin’ and then grabbed her hair and started whisperin’ in her ear. And then Sean - Sean told her to stop and she told Sean, “If you don’t like it, get out of my car.” So Sean got out of the car and walked away.

Rob Stafford, Dateline correspondent: Did you say anything at that point?

Cory Gregory: No, I just pretty much sat there and smoked my cigarette.

Stafford: They’re fighting over you.

Cory Gregory: Pretty much, yeah. I feel bad so I’m just being quiet, letting them do their argument.

It was later that afternoon that Adrianne’s parents discovered she was missing. And over the weekend, Cory told his mother about all the questions police were asking him and Sarah.

Teresa Gregory: And I just told him, “Well, you know, Cory, that’s an investigation. We have a missing girl here.” I figured she had run away. You know? I figured the kids maybe knew where she was, maybe knew where she was hiding. And I said, “Cory, if you haven’t done anything wrong, you don’t have anything to worry about.”

But by Monday afternoon, three days after Adrianne’s disappearance, Cory was making an unusual demand of his parents.

Teresa Gregory: That’s when Cory first told me “Sarah’s family has got her set up this afternoon with a lawyer and we need to get a lawyer.”

By Tuesday afternoon, they’d hired an attorney and Cory was at the police station talking with investigators.

Stafford: And what do you say to Cory as he goes in to give police a statement?

Bert Gregory, Cory's father: To tell the truth.

Teresa Gregory: To relax.

Bert Gregory: There’s no problem.

Teresa Gregory: Don’t be nervous.

Bert Gregory: The lawyer went in there with him and came out said he did real good. He answered all the questions. He says, “I don’t think it’s any big deal.”

Meanwhile, Adrianne’s parents were still desperately searching for their daughter, looking for clues—anything that would help find her.

Tony Reynolds, Adrianne's father: Just hungry I guess to find out something, somebody’s seen her somewhere or something.

They were so frantic, they’d even called a psychic.

Stafford: And what did he tell you?

Joanne Reynolds: That she was alive, living in a basement.

Tony Reynolds: The one time she needed you most, you wasn’t there.

Across town, Cory’s dad, was about to realize his teenager also needed help... and there was much more to the story than Cory had told the police.

Bert Gregory: He started crying. And I started asking him questions, and he started breaking down. He started crying more. So I knew something was up.

I just couldn’t even say anything. I just cried and hugged him. And he says, “Mom, I’m so sorry. I’m so sorry.” At that point my heart was so broken, I didn’t even have words.

Bert Gregory, Cory Gregory's father: I said, “Did something happen to her in that car?” And he started shaking his head, yes. He couldn’t talk.

The look on Cory Gregory’s face said it all. Four days after Adrianne Reynolds disappeared, it was clear Cory had been lying about what really happened. His father, Bert, braced himself for what his son was about to say.

Bert Gregory: I said, “Did she get hurt in the car?” Shook his head yes. I said, “Did she get hurt bad? He said really, really a lot.” I said, “Is she dead?” He shook his head yes. I said, “Well where’ she at?” He just couldn’t - he couldn’t talk.

Bert called Teresa, his ex-wife, and told her to come over right away.

Rob Stafford, Dateline correspondent: What do you say to Cory?

Teresa Gregory: I just couldn’t even say anything. I just cried and hugged him. And he says, “Mom, I’m so sorry. I’m so sorry.” At that point my heart was so broken, I didn’t even have words.

But Cory decided he did have something to say—something more about what had happened—and he wanted to say it to the police. His father reached for the phone.

Stafford: How difficult is the phone call you’re about to make?

Bert Gregory: Oh, I don’t know if it was difficult. It was the right thing needed to be done. A family needed to know where their daughter is. Things need to be straightened out. I mean you can’t hide something like this. It’s the right thing to do. He needs to face up to what he did, what his part was.

Teresa Gregory: He’d been holding it in all weekend. And he’d, he’d been trying to cover up their tracks all weekend, and I think it was just breaking him to do so that he just needed for his own peace to tell the truth.

Cory was ready to meet with the police for the second time.

Stafford: What is on the line for you at this point?

Cory Gregory: Well, pretty much my life, I guess. But you know I really wasn’t thinking about myself. You know I was thinking more about - I - I didn’t want to lose Sarah. I wanted to keep Sarah in my life. But I knew the right thing was to talk to the police for Adrianne’s sake and her family’s.

Cory was able to momentarily cast aside that power Sarah had over him and he provided police details of what really happened to Adrianne. Investigators captured every word on tape.

(Police interview) Cory Gregory: And we went to Taco Bell...

The tears from earlier that day were gone as Cory told a story that even the most hardened detectives found hard to fathom.

Cory Gregory: Then Adrianne grabbed her neck and started choking her.

Attorney: Adrianne grabbed Sarah’s neck?

Cory Gregory: Yes. And they both were struggling, and Sarah and Adrianne—struggling trying to choke each other....

Cory gave Dateline a more complete version of the final moments of Adrianne Reynolds' life.

Cory Gregory (to Dateline): They just started swinging at each other and then Adrianne hits Sarah in the nose. Sara’s nose started bleeding. So Sarah grabbed this wooden stick that she keeps in her car for def --- protection, she says, and started to hit her a couple times with it and they kept fighting and wrestling and it moved to the back seat.

At this point, Cory said he got out of the car and moved to the front passenger seat as the fight became more vicious.

Cory Gregory: Sarah’s on top of Adrianne and she choking Adrianne and then Adrianne goes out and Sarah gets off her and sits in the car - sits back in the front seat. We sit there and smoke a cigarette for awhile.

Stafford: You sit there smoking a cigarette at that point? And Adrianne is dead in the back seat of the car?

Cory Gregory: We thought she was just passed out. We were waiting for her just to wake up. And then finally we looked back and her face was blue and we just started freaking out after that, you know? We didn’t know what to do.

Stafford: And here’s Adrianne, your friend, who you had been out with just a couple days earlier.

Cory Gregory: Yeah.

Stafford: And she’s dead in the back seat of the car.

Cory Gregory: Yeah.

Stafford: Are you saying anything? Are you crying?

Cory Gregory: I—

Stafford: What are you doing?

Cory Gregory: I’m just sitting there. I couldn’t say anything. I was just shocked.

Stafford: But you’re incredibly unemotional about a lot of this.

Cory Gregory: I am really emotional, but I like to keep my emotions to myself, you know?

Remember: this all happened in broad daylight in a car parked at a busy taco bell. But because the windows were fogged up on a cold winter day, people right outside the car couldn’t see what was happening inside where panic was now setting in.

Stafford: So what are you going to do?

Cory Gregory: We don’t know. It’s like, “Man, what’s going on, Sarah? You killed her.” And she’s like, “No, she’s not dead. She’s not dead.” And it’s like, “Man, she dead, Sarah. What are we gonna do?” We’ve never been in trouble with the law. We don’t know nothin’ about it and then Sarah’s like, “You gotta help me hide the body - you gotta help me hide the body.” And you know, I was hesitant, but I told her, “Yeah, I’d help her out.”

Stafford: Why don’t you pick up the phone and call someone?

Cory Gregory: I just cared too much about Sarah. I didn’t want to see her spend the rest of her life in jail.

Stafford: You want to help Sarah. You don’t want to help Cory at that point?

Cory Gregory: At that time, no, because I didn’t think I had—

Stafford: Hard to believe.

Cory Gregory: Well that’s the truth. I figured you know, I’ll help her. I didn’t know what to do anyway. So I just followed along - did what she said.

Cory says that power, that control led him here - where he helped Sarah carry Adrianne’s body to the trunk of the car. They then drove out to Sarah’s grandparents’ farm. Cory says the plan was to bury Adrianne’s body, but the ground was frozen. So these two teenagers from the heartland were about to go to plan B.

Stafford: How would you describe what’s about to happen?

Cory Gregory: Horrifying, you know. It was worse than any horror movie you could watch. We were both in shock.

16-year-old Adrianne Reynolds was dead... and now Cory and Sarah were trying to hide the body. Cory says they wrapped it in a tarp and tried to bury it, but the ground was frozen so they moved onto Plan B.

Cory Gregory: We pour the gasoline on her and light her on fire.

Rob Stafford, Dateline correspondent: Who poured the gas?

Cory Gregory: I poured the gasoline on the tarp.

Stafford: Who lit the match?

Cory Gregory: It was a butane lighter. I used the lighter and lit it and then Sarah and I we just stood away and Sarah laid her head on my shoulder. She just started crying, you know, so I tried to sit there and comfort her.

Stafford: Are you crying, Cory?

Cory Gregory: I have tears rolling down but I wasn’t crying as hard as Sarah was at the time.

Stafford: Are you worried that someone’s gonna spot the fire?

Cory Gregory: No, we weren’t really even thinking of that. We figured since we couldn’t bury the body, the only proper thing to do would be cremate it.

Stafford: That’s ludicrous. It sounds like you were thinking of disposing the body so you didn’t get caught.

Cory Gregory: Well, at the time, we felt bad that she was dead and we were just trying to think of the proper way to do it.

Stafford: And that’s proper? I mean you dump her body and put gas on it?

Cory Gregory: No, that’s not proper, but at the time, you know, we ain’t really thinking. We’re freaked out.

But Plan B wasn’t working either. Adrianne’s body was not turning to ashes as they thought it would.

Stafford: So what’s the plan now?

Cory Gregory: Sarah decides we need to get the body off the land and says, “We gotta cut the body up.” Sarah’s trying to talk me into doing it. I’m like, “No, you know, I can’t do that, you know.” Lighting a fire’s one thing, but I can’t cut up a body. It ain’t right.

Stafford: None of this is right, Cory.

Cory Gregory: I know, I know, none of this is right, but I told her, “I can’t do this, you know. I won’t do it.

But Cory and Sarah knew another boy who they thought would be perfect for the job. His name was Nate Gaudet.

Cory Gregory: Nate’s into blood and gore. He was the type of kid that’d go around killing animals and stuff, so Sarah figured he might help.

The next day, Saturday, they picked Nate up, told him about Adrianne, and asked him if he would cut up the body so they could move it.

Cory Gregory: He said he would.

Stafford: All of this is really hard to fathom. This guy had nothing to do with Adrianne’s murder?

Cory Gregory: No.

The next day, Sunday they picked Nate up and had him bring a saw.

Stafford: How would you describe what’s about to happen?

Cory Gregory: Horrifying, you know. It’s worse than any horror movie you could watch. It was unbearable, you know.

Cory says he and Sarah talked about music—anything—to keep their minds off what was happening in front of their eyes. Nate was sawing off the head, arms and legs and cut the torso in half. They dumped most of Adrianne’s remains in a ravine on the farm and covered them with branches. Cory says he held open a trash bag as Nate placed the head and arms inside. The gruesome job complete, they put the bag in the trunk of Sarah’s car and then drove to a McDonald’s to get a bite to eat.

Stafford: How are you able to eat after?

Cory Gregory: We were high.

Stafford: —participating in something like that?

Cory Gregory: We were high. We were smoking weed all day.

Stafford: What did you have?

Cory Gregory: Ah, a double cheeseburger.

From there, they drove to a park called the Black Hawk Historic Site, looking for a place to bury the bag with the head and arms they worried could be identified as Adrianne’s.

Cory Gregory: Nate’s got the bag in one hand and then he’s holding the shovel under his trench coat and he just started running through the woods. Sarah found a place and she told us to start digging there.

During his taped interrogation, Cory agreed to show police exactly where they buried Adrianne’s remains. Just after 11 p.m., four days after her disappearance, Cory led authorities down a steep icy path. Under a pile of dirt, police found a manhole cover and several feet below... the bag. At 2 a.m., police called Adrianne’s parents.

Joanne Reynolds, Adrianne's step mom: They said, “This is the police and we’re at your front door.” And I felt like my stomach had just dropped.

Tony Reynolds, Adrianne's father: It seemed like everything was in slow-motion. It’s the worst feeling I’ve ever had. I didn’t believe it for a long time.

The next morning, Cory led police to the place on the farm where Adrianne’s body had been burned and her other remains hidden. It wasn’t until Thursday, after both Cory Gregory and Sarah Kolb were arrested that Adrianne’s parents learned about the dismemberment.

Tony Reynolds: I never cried so much in my life. I mean the murder was bad enough but what they did after is the hard part. That takes a sick person to take a saw and cut somebody up. I couldn’t do it to a dog, much less a human and I don’t know anybody that could, especially at 16 years old.

Cory’s parents were also appalled.

Teresa Gregory: I’ll never understand how they, how they just could disconnect their feelings and commit the concealment that they committed because that’s so gruesome. It’s just not Cory at all.

Stafford: A lot of parents would say this could never ever, ever happen to my son.

Teresa Gregory: I hope nobody ever thinks that because you’re fooling yourself. I think that no family is exempt from this kind of horror hitting their family because teenagers are at a place where they’re trying to find themselves in life.

Police (police interview): And where were you?

Cory Gregory: I was in the back seat looking out the window.

Police: Just looking out the window while they were fighting?

Cory: Yes.

Rob Stafford, Dateline correspondent: Cory, in his videotaped statement, said that while Adrianne was being murdered, he was looking out the window and Sarah was doing everything. Do you believe that?

Tony Reynolds, Adrianne's father: No, not for a second. There’s no way that Sarah Kolb could’ve did it by herself. No way. It wouldn’t have happened if it wasn’t for Sarah. Cory had no reason to kill her. But it took both of them to do it.

While Cory Gregory was blaming Sarah Kolb, Sarah was blaming Cory. In November 2005, she went on trial and Adrianne’s parents attended every day searching for some sign of remorse.

Joanne Reynolds, Adrianne's stepmom: She always had a smirk on her face. She would walk in and just kind of like, “Here I am!”

Tony Reynolds: I looked at her the whole time. She never ever made eye contact with me.

Sarah took the stand in her own defense admitting only that she pulled Adrianne’s hair during the fight in the car and testifying that Cory was the one who snapped, suddenly attacking Adrianne without warning. Prosecutor Jeff Terronez described her testimony.

Jeff Terronez, prosecutor: Out of nowhere, from the back seat, Cory says, “She’s not one of us, Sarah” and begins to choke Adrianne to death from behind.

Stafford: Cory initiates the attack, according to Sarah.

Terronez: According to Sarah, Cory puts a belt around Adrianne’s neck in the back seat and holds it as a noose around Adrianne’s neck to make sure that Adrianne is dead.

Sarah then testified Cory threatened to kill her, her family, even her cats, if she didn’t help him conceal the crime. The prosecutor says clearly Sarah was lying, but Cory has also been minimizing his role in the murder.

Stafford: So what do you think really happened that day?

Terronez: I think that Adrianne probably said some words that upset Sarah. I think that Sarah attacked Adrianne. I think that Adrianne defended herself.

The prosecutor’s theory? As the girls fought, Cory held Adrianne’s arms as Sarah choked her. When Adrianne passed out, Cory picked up the belt.

Terronez: Cory placed it around Adrianne’s neck and made sure she was dead.

Stafford: You believe Cory fully participated in this murder?

Terronez: Absolutely.

Stafford: Who was the leader of this attack?

Terronez: Clearly Sarah.

He says Sarah was the only person with a motive: jealousy.

Stafford: Your motive comes down to just a teenage lovers’ quarrel that teenagers in every school in the country have every single day.

Terronez: It’s a powerful emotion. Very powerful emotion. People act differently upon it.

Stafford: This is a small town. And these kids have no criminal histories of any significance.

Terronez: Ordinary humans being consumed by emotion. It’s that simple. Cory took part because of his love for Sarah. Sarah did what she did because of her hatred and disdain towards Adrianne.

Sarah’s trial ended in a hung jury. But in a retrial, she was convicted of murder and concealing a homicide.

Tony Reynolds: I don’t know how anybody can hate anybody that much. But why did they have to kill her?

In August, a judge sentenced Sarah to 53 years in prison.

Nate Gaudet pleaded guilty to concealing a homicide and was sentenced to up to five years.

Tony Reynolds: It doesn’t matter what they do, Adrianne’s still not coming home. I usually run three miles every day and every step of it, I think about it.

Cory Gregory pleaded guilty to the murder and concealment and received a 45-year sentence. Though he apologized in court to Adrianne’s family, he still insists he did not kill her, admitting only to holding the belt he says Sarah put around Adrianne’s neck after she was dead.

Cory Gregory: It wasn’t really tight, I was just holdin’ it in my hand. I thought she was dead, so it didn’t really make a difference in my mind.

Stafford: Cory, I can understand why you’d want to minimize something as horrible as this, but to listen to your story you basically were just along for the ride.

Cory Gregory: I been doing what Sarah wanted to do for the past like six, seven months, anything Sarah wanted to do.

Stafford: But this is different. Isn’t this really about what’s gonna save you and Sarah from going to prison for the rest of your life?

Cory Gregory: Nah. The only thought in my mind was you know, “I’m gonna help my friend. She accidentally killed somebody and I’m gonna help her.”

That loyalty and love for Sarah Kolb—and her control and power over him—ended Adrianne’s life and Cory’s future. So how does he feel now toward the girl who blames him for both the killing and the cover-up?

Stafford: Do you still love Sarah?

Cory Gregory: I guess you could say that. She ain’t my main priority like she was at the time.

The days of getting high and hanging out with Sarah are long gone — replaced by endless hours in a prison cell. For the two families, and two fathers shattered by this grisly crime, life can feel just as lonely.

Stafford: What’s been the hardest part for you, Bert?

Bert Gregory: Well, I won’t be able to see him much. I’ll see him in prison the rest of his life. I mean, I’m 49 years old. I ain’t going to live to be 89. It’s just hard.

Even harder on the man who still writes poems to the daughter he’ll never see again.

Tony Reynolds: "You were dealt to be my daughter. I was dealt to be your dad. And no matter how the game turned out, you’re the best hand I ever had. P.S. I love you—and I’m proud to be your dad."

Sarah Kolb is appealing her sentence. Cory Gregory has filed a motion, asking that the judge vacate his guilty plea so that he can be granted a new trial.

Dateline wires the home of a volunteer, Jenny, from top to bottom with hidden cameras. Then she called repairmen to her house for a simple problem we created as a test with Jenny's pool. NBC's Chris Hansen reports.